Biomedical subjects

James M Watters

Publications and source records attributed to James M Watters.

4 recordsLinked to original sources

PubMed2005

Insulin responses to glucose and isoproterenol decrease with age.

BACKGROUND: Older trauma patients are less tolerant of glucose loads than are young patients, in part as a result of diminished insulin response. We hypothesized that diminished insulin responses result from reduced pancreatic sensitivity to beta-adrenergic stimulation. METHODS: We studied healthy subjects prospectively at a clinical investigation unit, to compare young (n = 6, mean age 21 [standard deviation {SD} 2] yr) and older people (n = 6, mean 63 [SD 2] yr). Paired studies of isoproterenol infusion, alone and in conjunction with a 2-hour hyperglycemic glucose clamp, were conducted in each subject. Heart rate, serum insulin concentration and other hemodynamic, biochemical, and physiologic variables were measured. RESULTS: Heart rate increased less markedly in response to isoproterenol in older than in young subjects (p < 0.01). Serum insulin during infusion accompanied by hyperglycemic clamp was also lower (467 [SD 135] pmol/L in older v. 755 [SD 284] pmol/L in young subjects, p < 0.05), despite similar hyperglycemia. Whole-body disposal of exogenous glucose was lower in older (5.8 [SD 1.7] mg/kg/min) than in young subjects (9.6 [SD 3.9], p < 0.05). CONCLUSIONS: Heart rate and serum insulin responses to combined isoproterenol infusion and glucose loading were both lower in healthy older subjects than in the young. Diminished tissue sensitivity to beta-adrenergic signals may contribute to the impaired insulin response and exaggerated glucose intolerance displayed by older patients after injury and during acute illness.

Adrenergic beta-Agonists↗

PubMed2005

Predictors of referral for adjuvant therapy for colorectal cancer.

OBJECTIVE: We carried out a retrospective cohort study at the Ottawa Hospital-Civic Campus to determine the proportions of patients referred for and provided adjuvant therapy for colorectal cancer (CRC) among those eligible according to published clinical practice guidelines. METHOD: Patients with stage III colon or stage II or stage III rectal cancer who had had potentially curative surgical resection for CRC and were seen at the Ottawa Hospital during 1999 and 2000 were eligible. We noted the number of medical or radiation oncology consultations, or both, and the subsequent receipt of adjuvant chemotherapy or radiotherapy, or both. RESULTS: Of 158 eligible patients, 135 (85%) had medical or radiation oncology consultations, or both. Of the total, 104 were less than 75 years of age and of these 99 (95%) were referred; of the 54 patients 75 years of age or older, 36 (67%) were referred. Of the 158 patients, 113 (72%) received adjuvant therapy, 90 (87%) eligible patients aged less than 75 years and 23 (43%) older patients. Increasing age and the presence of comorbidity were independent predictors of nonreferral and nontreatment. Gender and cancer site (colon or rectum) were not significant predictors of referral for, or receipt of, adjuvant therapy in general. CONCLUSIONS: The observed rates of referral for and receipt of adjuvant therapy for CRC are greater than generally published and appear reasonably concordant with current clinical practice guidelines, but optimal rates are undefined. Older patients and those with comorbidity were less likely to be referred and treated. However, our knowledge of the factors important to the process of clinical decision-making about adjuvant therapy for CRC is incomplete, and there may be patients, especially older ones, for whom adjuvant therapy would be appropriate but who are not being referred or treated.

Aged↗

PubMed2002

Limited effects of micronutrient supplementation on strength and physical function after abdominal aortic aneurysmectomy.

BACKGROUND: Tissue injury following ischemia-reperfusion is mediated in part by free oxygen radicals. We hypothesized that perioperative micronutrient supplementation would augment antioxidant defenses, minimize muscle injury, and minimize postoperative decreases in muscle strength and physical function following abdominal aortic aneurysmectomy. SETTING: A university-affiliated hospital and regional referral center. DESIGN: A randomized, double-blind, placebo-controlled trial of supplementation with beta-carotene, vitamins C and E, zinc, and selenium for a period of 2-3 weeks prior to surgery and 1 week thereafter. STUDY POPULATION: Patients undergoing elective abdominal aortic aneurysmectomy (n=18 per group). PRINCIPAL MEASUREMENTS: Handgrip and other measures of strength and physical function. RESULTS: Handgrip and quadriceps strength decreased following surgery, but not to a significantly different extent in the placebo and supplemented groups. Self-rated physical function decreased following surgery in the placebo group and was preserved in the supplemented group. CONCLUSIONS: Perioperative supplementation with micronutrients with antioxidant properties has limited effects on strength and physical function following major elective surgery.

Adult↗

PubMed2002

Surgery in the elderly.

The elderly (those 75 years of age or older) are a heterogeneous group. They present with both elective and urgent surgical problems, and risk assessment, decision-making and perioperative care are typically more challenging than in younger patients. An appreciation for this heterogeneity and an understanding of how physiologic changes of aging affect surgical care are essential if the best outcomes are to be achieved.

Age Factors↗